Mass Properties window

Used to control and display mass properties analysis of the length, area, or volume measured with the Measure Length tool, Measure Area tool, or Measure Volume tool. This window opens when the Mass Properties tool setting is turned on.

Mass Properties window, displaying only the part that is always visible — the basic properties

Mass Per <Length/Area/Volume>

Sets the mass per master unit as follows, depending on which measuring tool is selected:

Tool selected	Sets
Measure Length	Mass Per Length — the linear density per master unit.
Measure Area	Mass Per Area — the area density per square master unit.
Measure Volume	Mass Per Volume — the volumetric (mass) density per cubic master unit.

This setting affects both the Mass and Moments of Inertia.

File menu > Save…

Open the Save Measurement Values dialog box, which is used to save the mass properties analysis in a text file.

Display menu > Moments and Products of Inertia

Toggles the display of the part of the Mass Properties window that shows moments and products of inertia.

Item name	Shows for measured element(s)
Moments of Inertia	Mass moments of inertia — useful for kinematic analysis, including calculating the force required to rotate a body about an axis.
Products of Inertia	Mass products of inertia.

Part of the Mass Properties window that shows Moments and Products of Inertia

For closed, planar elements, the area moments of inertia are obtained by setting Mass Per Area to 1.0. In this case, the area moments are displayed as master units to the fourth power. The area moments are required for analyzing the stress across a beam cross section and other areas of engineering analysis.

The combination of the mass moments and polar moments of inertia are commonly referred to as the inertia tensor.

The combination of moments and products of inertia about a given coordinate system can be used to calculate these values for any coordinate system.

Display menu > Principal Moments

Toggles display of the part of the Mass Properties window that shows Principal Moments and Principal Directions.

Item name	Shows for measured element(s)
Principal Moments	The maximum, minimum and an intermediate moment of inertia.
Principal Directions	The three mutually perpendicular axes extending from the centroid along which the maximum, minimum and an intermediate moment of inertia occur. The products of inertia about these axes is zero.

Part of the Mass Properties window that shows Principal Moments and Directions

Display menu > Radii of Gyration

Toggles display of the part of the Mass Properties window that shows the Radii of Gyration, which are an alternate way to express the Moments of Inertia as distances in working units.

Part of the Mass Properties window that shows Radii of Gyration